Plasma, LCD, LED: Understanding the Basics

A visit to an electronic shop can be a particularly harrowing experience. You are surrounded by hundreds of electronic gadgets of all shapes, sizes, brands and prices and in the middle of all this, you are expected to make an informed choice. For example, you go to the nearest electronic store to buy a new television set for your home. Once you get there, you are introduced to the different kinds of TVs- plasma, LCD, LED etc. On top of that, a number of technical terms like HDD, CCFL will be thrown at you randomly until you find yourself completely lost. Well, it is not as bad as it sounds. We will take you through the very basics of the world of television, so that the next time you want to buy a television set, you are equipped with all the necessary details.

Let’s begin with the biggies- Plasma, LCD and LED. What exactly is the difference between them? When Hi-Definition TV or HDTV as it is commonly known was introduced, plasmas had just arrived on the market. These were backed by flat panel technology which produced top notch picture quality. It created quite a rage in the electronic market, after which it gave way to the world of LCDs. As of now, LCDs and LEDs are the two major players in this field.

True to its name, LCD or Liquid Crystal Display works through a liquid which is enclosed between two plates. This liquid becomes dynamic when it receives current in some form, and hence the picture is formed. While black and white LCDs have been around for quite some time, color LCDs is a relatively recent phenomenon. Now, the liquid used in this technology does not illuminate by itself and thus, an external source of light is needed. This is where LEDs come into the picture, quite literally.

If one was to go by strictly technical standards, the term LED would come across as a misnomer. LEDs are actually just specialized versions of LCDs. The basic technology has remained the same, only the source of lighting has changed from the traditional CCFLs (Cold Cathode Fluorescent Lighting) to LEDs or Light Emitting Diodes.

LEDs offer many advantages due to the different types of back lighting available- edge lighting, direct lighting and local dimming. In the former case, LEDs are positioned along the edge of the panel and this facilitates the production of extremely thin screens as the LEDs are not placed behind the screen, which is precisely the case in direct lighting. Direct Lighting has its own advantages, the biggest of them being that the color contrast can be enhanced by turning some LEDs off. Local dimming, which is a very recent phenomenon, attempts to combine these two types. Under this technology, there are banks of LEDs which are positioned behind the panel, and thus, the contrasts can be regulated. At the same time, due to the presence of specialised banks of LEDs, it is possible to have a thin screen depth.

Due to such developments in technology, LEDs have added a new dimension to the world of television. The quality of color accuracy, contrast levels and viewing angles have improved by leaps and bounds, thus re-defining the whole experience of watching television.